Four-point +ve charges of the same magnitude (Q) are placed at four corners of a rigid square frame as shown in the figure. The plane of the frame is perpendicular to Z-axis. If a –ve point charge is placed at a distance z away from the above frame (z<<L) then
1. – ve charge oscillates along the Z-axis.
2. It moves away from the frame.
3. It moves slowly towards the frame and stays in the plane of the frame.
4. It passes through the frame only once.
A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The total flux for the surface of the cylinder is given by
(1)
(2)
(3)
(4) Zero
Electric field at a point varies as r0 for
(1) An electric dipole
(2) A point charge
(3) A plane infinite sheet of charge
(4) A line charge of infinite length
Total electric flux coming out of a unit positive charge put in air is
(1)
(2)
(3)
(4)
A cube of side l is placed in a uniform field E, where . The net electric flux through the cube is
(1) Zero
(2) l2E
(3) 4l2E
(4) 6l2E
Eight dipoles of charges of magnitude \((e)\) are placed inside a cube. The total electric flux coming out of the cube will be:
1. \(\frac{8e}{\epsilon _{0}}\)
2. \(\frac{16e}{\epsilon _{0}}\)
3. \(\frac{e}{\epsilon _{0}}\)
4. zero
A charge q is placed at the centre of the open end of the cylindrical vessel. The flux of the electric field through the surface of the vessel is
(1) Zero
(2)
(3)
(4)
Electric charge is uniformly distributed along a long straight wire of radius \(1\) mm. The charge per cm length of the wire is \(Q\) coulomb. Another cylindrical surface of radius \(50\) cm and length \(1\) m symmetrically encloses the wire as shown in the figure. The total electric flux passing through the cylindrical surface is:
1. | \(\dfrac{Q}{\varepsilon _{0}}\) | 2. | \(\dfrac{100Q}{\varepsilon _{0}}\) |
3. | \(\dfrac{10Q}{\pi\varepsilon _{0}}\) | 4. | \(\dfrac{100Q}{\pi\varepsilon _{0}}\) |
The S.I. unit of electric flux is
(1) Weber
(2) Newton per coulomb
(3) Volt × metre
(4) Joule per coulomb
Shown below is a distribution of charges. The flux of electric field due to these charges through the surface S is
(1)
(2)
(3)
(4) Zero